Enterotoxigenic and genetic profiles of Bacillus cereus strains of food origin in Brazil.
In Brazil, the incidence of Bacillus cereus outbreaks is unknown, and there is little information about B. cereus occurrence in food. In addition, data on toxin production and genetic characterization of the B. cereus isolates cannot be found. This pathogen causes two distinct types of toxin-mediated foodborne illnesses known as diarrheal and emetic syndromes. Diarrheal syndrome has been linked to three different enterotoxins: two protein complexes, hemolysin BL (HBL) and nonhemolytic enterotoxin (NHE); and an enterotoxic protein, cytotoxin K (cytK). Emetic syndrome is related to cereulide, a toxin encoded by the ces gene. In this study, NHE and HBL production capacities of 155 strains of B. cereus isolated from Brazilian food products were evaluated with an immunoassay. Strains were also tested for the presence of the genes of the HBL and NHE complexes, cytK, cytK-1, cytK-2, and ces, using PCR. HBL was detected in 105 (67.7%) strains and NHE in 154 (99.4%) strains. All the strains harbored at least one gene of the NHE complex, while 96.1% of them were positive for at least one of those of the HBL complex. Genes cytK1 and ces were not detected. All strains showed toxigenic capacity and could represent a risk for consumers if good practices are not followed. This is the first report on toxigenic and genetic profiles of B. cereus strains isolated in Brazil.
Aragon-Alegro
Lina Casale
LC
Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 580, bloco 14, 05508-900, Sao Paulo, SP, Brazil.
Palcich
Gabriela
G
Lopes
Graciela Volz
GV
Ribeiro
Vinícius Buccelli
VB
Landgraf
Mariza
M
Destro
Maria Teresa
MT
D001409:Bacillus cereus / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003257:Consumer Product Safety; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D047630:Depsipeptides / Q000378:metabolism; D004639:Emetics / Q000378:metabolism; D004768:Enterotoxins / Q000096:biosynthesis* / Q000235:genetics*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005784:Gene Amplification; D006460:Hemolysin Proteins / Q000378:metabolism; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods
D004269:DNA, Bacterial; D047630:Depsipeptides; D004639:Emetics; D004768:Enterotoxins; D006460:Hemolysin Proteins; C089294:cereulide